Answer:
A worked 20 hours and B worked 15 hours.
Explanation:
Given:
Mechanic A hourly rate = $55
Mechanic B hourly rate = $45
Total charged = $1775
Let's assume Mechanic A worked 'A' amount of hours and Mechanic B worked 'B' amount of hours, then
Step 1:
First equation: A + B = 35
Second equation: 55xA + 45xB = 1775
Step 2:
First equation can be written as: A = 35 - B
Step 3: Replace value of A in second equation
Second equation: 55x(35-B) + 45B = 1775
: 1925 - 55B + 45B = 1775
: (1925 - 1775 )/10 = B
: B = 15 hours
A worked = 35 - 15
= 20 hours